Advanced detection and compensation scheme for current transformers saturation

This paper presents an advanced technique for current transformer saturation detection and compensation. The technique is based on the pre-fault current signal and the saturated-free portion after fault occurrence in order to calculate the effective unknown parameters of the transient secondary current. The proposed technique has attractive features include a high accuracy to determine power system angle, the simplicity for on-line implementation, not affected by the remanent flux in the CT core, and it is independent of the CT parameters/characteristics and secondary burden. The accuracy and robustness of the introduced compensation algorithm are demonstrated though extensive simulation cases reflecting a wide range of variation in fault conditions and CT parameters.